The following description includes information that may be useful in understanding the present invention. It is not an admission that any of the information provided herein is prior art or relevant to the presently claimed invention, or that any publication specifically or implicitly referenced is prior art.
In the 1980s, various groups began attempting to decentralize the lab and hospital system. Particularly, the semiconductor industry originally developed the early stage concepts of microfluidic and microfluidic devices (the so called “lab on a chip”).
The use of silicon etching procedures, developed for microelectronics industry, allowed the manufacture of the first device containing mechanical micro-elements integrated on a silicon wafer. These new types of devices called MEMS (Micro Electro Mechanical Systems) gave rise to industrial applications, particularly in the field of pressure sensors, printer heads, and other micro engineering applications.
In the 1990s, applications of MEMS in the biology, chemistry, and biomedical fields evolved. A major research effort was made to develop laboratories on a chip to enable the integration of almost all the processes required for complete biological, chemical and biomedical protocols on a single microfluidic chip. At that time, the majority of microfluidic devices were still made of silicon or glass, and thus, required the heavy infrastructure of microelectronics industry. http://www.elveflow.com/microfluidic-tutorials/microfluidic-reviews-and-tutorials/microfluidics-and-microfluidic-device-a-review/
Therefore since 1990s, polymers such as a PDMS based disposable microfluidic chip/cartridges have been developed. PDMS could be manufactured by the soft lithography process. Accordingly, PDMS based microfluidic chip/cartridges were much preferred by researchers in academia since it was easier and faster to manufacture the prototypes than the traditional polymer injection molding process. Also the soft lithography process used to manufacture the PDMS chip is much more sophisticated than other methods. Thus, the MEMS could be made with components on the nanoscale to save significant amount of human samples, buffer solutions, reaction mix, primers, etc.
However, a PDMS based microfluidic chip has major drawbacks. For instance, the manufacturing process is labor intensive, and is difficult to mass produce. This makes the total manufacturing cost of a disposable chip relatively expensive at the commercialization phase.